Ink ribbon mechanism for typewriters and like machines



Feb. 21, 1939- J. P. OHALLORAN 2,143,217

INK RIBBON MECHANISM FOR TYPEWRITERS AND LIKE MACHINES Original Filed March 24, 1937 2 Sheets-Sheet l Feb. 21, 1939. p. QHALLORAN I 2,148,217

INK RIBBON MECHANISM FOR TYPEWRITERS AND LIKE MACHINES Original Filed March 24, 1937 2 Sheets-Sheet 2 Fahd. 4 4.1%...

Patented Feb. 21, 1939 UNITED STATES PATENT OFFICE.

INK RIBBON MECHANISM FOR TYPEWRIT- ElltS AND LIKE MACHINES Joseph Patrick OHalloran, Landon, England, assignor to Okopa Carbon Paper Eliminator himited, London, England January 2, 1937 6 Claims.

This invention relates to attachments for typewriters, calculating machines and the like of the kind in which an auxiliary ink ribbon is employed in additionto the'main ink ribbon, for the purpose of making an orginal and one or more copies without the use of carbon paper.

It is important to provide means whereby the auxiliary ribbon can be kept at a sufficient tension to prevent it from sagging and soiling the paper, and also to permit the sheets of paper to run into their proper positions in relation to the ribbons, and the object of the invention is to provide a tensioning device for this purpose.

According to the invention the ends of the auxiliary ribbon are wound on spools, one of which is provided with means for winding the ribbon on to it from the other spool at the conclusion of the typing of a line, and the other of which is provided with a spring which opposes the winding operation aforesaid. This spring serves to hold the ribbon at the proper tension and affords a means for rapidly rewinding the ribbon when it is necessary to do so. Preferably the first-mentioned spool is driven by a pawl and ratchet mechanism under the control of the linespacing mechanism.

One form of ribbon tensioning device for the auxiliaryribbon will now be described in detail with reference to the accompanying drawings; It is to be understood, however, that I do not limit my invention to the details of construction illustrated whichare given by way of example only. In the drawings:--

Fig. 1 is a perspective view showing the device fitted to a typewriter of conventional construction,

Fig. 2 is a section through the platen of the typewriter showing how the paper sheets are fed into proper position relatively to the main and auxiliary ribbons,

Fig. 3 is a perspective view of the separating p Fig; 4 is a plan view of the drum for the left hand auxiliary ribbon spool,

Fig. 5 is a view looking in the direction of the arrow A in Fig. 4,

Fig. 6 isa plan view of the drum for supporting the right hand spool,

Fig. 7 is a section on the line VII-VII in Fig. 6 showing the spring unwound, and

a Fig. 8 is a section on the line VIIIVIII in Fig. l, but with the spring fully wound.

Like reference numerals indicate like parts throughout the drawings.

.The typewriter maybe of any standard type,

and comprises a fixed body portion II] on which is supported the usual traveling carriage ll carrying the platen l2. The machine includes the usual typewriter keys l3, type bars I4, spools It:

for the main ribbon It, and ribbon vibrator H.

are attached respectively to the carriage and to the body of the machine, with guides 22, 23 for the auxiliary ribbon, and with a paper separating pan 24. The guides 22, 23 are fixed by screws 25 to the. carriage, and the guide 22 carries a bracket 2% for supporting the spool 8. The spool i8 is supported by a bracket 21 attached to the side of the body portion of the machine by screws 28 (see Fig. 7). The top bar 29 of the pan it is attached to thecarriage by screws 38, and carries four downwardly projecting shield members H which extend around the platen l2 inside the paper guide 32 (see Fig. 2) and serve to feed the sheets of paper to correct position. The upper end of each shield member M is thinned to a fine edge at 33, these edges being located just behind the lower edge of the auxiliary ribbon 28 when the parts are assembled.

In order to make two copies three sheets of paper a, b, c are inserted into the machine at the top as indicated in Fig. 2, and caused to travel around to the printing line by turning the platen by means of the knob 34. As will be seen the pan 24 diverts the front two sheets into position between the two ribbons, while the rear sheet a is brought into position behind the auxiliary ribbon 28. An original imprint of the matter typed will then be made on the front surfaces of the sheets a, c and on the rear surface of the sheet (b, which should be of thin paper so that thematter typed on it can be read from the front. If extra copies are required these may be made with carbon paper between the sheet a and the platen in the ordinary way. The transparent sheet I) can be omitted if desired but in this case it is desirable to introduce a shield of Celluloid or other the paper solely by means of a spring 35 associated with the spool l9, no guide extending along the printing line being necessary. The spool l9 carries a downwardly projecting pin 36 adapted to engage a hole 31 in a plate 38 fixed to a spindle 39 rotatably mounted in the bracket 21. The spool I9 is held in position on the spindle 39 by a detachable screw cap 40. The lower end of the spindle 39 passes through a drum 4| containing the spring 35 and having a projecting lug 42 which coacts with the bracket 21 to hold the drum against anti-clockwise rotation as seen from above, and thereby permits the spring to be wound up on anti-clockwise rotation of the spindle I9, as the auxiliary ribbon 20 is drawn over to the other spool l8.

Inside the drum 4| is a sleeve 43 rotatably mounted on the spindle 39 and having a tooth 44 Which co-operates with a pin 45 on the spindle. The sleeve 43 is attached to the inner end of the spring 35 by means of the screw 46. The outer end of the spring 35 is attached by a rivet 47 to a split ring 48 sprung within the drum 4|.

As the auxiliary ribbon is unwound from the spool I9, the spindle 39 will be turned anticlockwise with the result that the pin 45 will turn the sleeve 43 anticlockwise, thus winding .up the spring 35. The attachment of the outer end of the spring to the split ring 48 instead of to the drum itself permits of a certain amount of slip between the spring and the spool box, and enables the spring to deal with a very large length of ribbon without danger of breaking.

A certain length of the auxiliary ribbon is wound over from the spool I9 to the spool l8 on actuation of the line space lever 56 at the conclusion of the typing of a line. This is done as follows:

The spool I8 is loosely mounted on a spindle 59 journalled in a U-shaped bracket 49 fixed to the bracket 26. To the bracket 49 is attached an angle member 5|, the upright limb of which is connected to a U-shaped frame 52, in which is journalled a vertical spindle 53. To the spindle 53 is fixed a crank 54, pivoted to a link 55 by which it is connected to the line space lever 56. To the lower end of the spindle 53 is fixed a crank 51 connected by a link 58 to a U-shaped lever 59 journalled on the spindle 50. On the lever 59 is pivoted a pawl 69 which co-operates with a ratchet 6| fixed to the spindle 50, and co-operating with a check pawl 61.

On actuation of the line space lever therefore, movement is communicated through the members 55, 54, 53, 51, 58, 59, 69 to the ratchet wheel 6| to cause it to rotate clockwise as seen from above. A pin 62 on the lower surface of the spool |8 normally engages with one of three holes 63 in a plate 66 fixed to the spindle 50, the spool being held with its pin so engaged by the screw cap 64. Consequently the spool l8 partakes of the clockwise movement of the spindle, thereby unwinding ribbon from the spool l9 against the action of the spring 35, the spring continually holding the ribbon taut. When it is desired to return the ribbon to the spool Hi, the screw cap 64 is slackened, whereupon a leaf spring 65 lifts the spool l8 until its pin 62 is clear of the hole in the plate 66, thus uncoupling it from its pawl and ratchet drive and enabling it to rotate counter-clockwise, with the result that the ribbon is wound back on to the spool H! by the spring 35.

In typewriters or the like operating with an auxiliary inking ribbon, it has been the practice to fit round the platen a curved sheet of metal or other suitable material such as 24 and known as the pan, which serves to separate the sheets to be typed upon by the main and auxiliary ribbons. It has so far been the practice to provide on the front face of the pan, in front of the platen, a guide or ledge for supporting the auxiliary ribbon, with the result that when capitals are being typed, an impression of the small letter carried on the type-bar beneath the capital is received, through the thickened portion of the pan below the ledge, on the paper behind the pan.

By the provision of the tensioning device for the auxiliary ribbon according to the invention, I am able to overcome this difiiculty, because since the pan no longer has to support the auxiliary ribbon, its front portion can be thinned down at 33 to an extent such that while still serving to separate the sheets of paper, there is no longer any danger of it being struck by characters on the type-bars below those which are printing.

A further important advantage of the chamfering of the edge of the pan at 33 is that this leaves room for the auxiliary ribbon to travel past the paper without the paper being bulged by the pan into contact with the ribbon. It also obviates any risk of the auxiliary ribbon being lifted with the paper, when the platen is turned on opera tion of the line spacing lever.

The auxiliary ribbon tensioning device according to the invention can of course be employed in conjunction with calculating, accounting or like machines in addition to typewriters, and the term typewriting machine used in the appended claims is to be understood as including such other machines in addition to typewriters.

What I claim as my invention and desire to secure by Letters Patent is:-

1. The combination with an auxiliary ribbon spool for attachment to a typewriting machine of a spindle, means for detachably coupling the spool to the spindle for rotation therewith, a coiled spring operatively connected at one end to the spindle, a drum surrounding the spring, and a split ring sprung into the interior of said drum and connected to the other end of said spring.

2. The combination as claimed in claim 1, in which the drum is rotatably mounted on the spindle, the drum having a lug co-operating with a fixed stop to restrict rotational movement of the drum on movement of the spindle in the direction to wind up the spring.

3. In a typewriting machine comprising a fixed body portion, type bars mounted thereon, a paper carriage slidable on said body portion, a platen rotatably mounted on said carriage and a line space lever, the combination of a pair of ribbon spools, one at least of which is mounted on the carriage, driving means for effecting, on actuation of the line space lever, intermittent rotation of said carriage-carried spool to wind ribbon thereon from the other spool, a spring associated with said other spool for holding said ribbon in tension, and release means for uncoupling the first-mentioned spool from its driving means to permit of uninterrupted reverse feed of the ribbon by the spring.

4. In a typewriting machine comprising a fixed body portion, type bars mounted thereon, a paper carriage slidable on said body portion, a platen rotatably mounted on said carriage and a line space lever, the combination of a pair of ribbon spools, one of which is mounted on the carriage and the other of which is mounted on the body portion, driving means for effecting, on actuation of the line space lever, intermittent rotation of said carriage-carried spool to wind ribbon thereon from the other spool, a spring associated with said other spool for holding said ribbon in tension, and release means for uncoupling the first-mentioned spool from its driving means to permit of uninterrupted reverse feed of the ribbon by the spring.

5. The combination, with an auxiliary ribbon spool for attachment to a typewriting machine, of a driving spindle for the spool, means constituted by a screw cap fitting on to the end of the spindle, for coupling the spool to the spindle for rotation therewith, driving means for imparting intermittent rotational movement to the spindle, and release means for uncoupling the spool from the spindle to permit the spool to rotate freely on the spindle, said release means comprising a spring which is held inoperative when the screw cap is in position, but is freed to uncouple the spool from the spindle on slackening of the screw cap.

6. The combination with an auxiliary ribbon spool for attachment to a typewriting machine, of a driving spindle for the spool, a spring acting to uncouple the spool from the driving spindle, and a coupling device which is operable to render the spring ineffective and couple the spool to the spindle for rotation therewith, and which is movable to a release position, in which the spring is freed to uncouple the spool from the spindle.

JOSEPH PATRICK OHALLORAN. 

